The procedure is 'mostly' the same, however there's some additional options with this release.
Skins, by default, are stored in the DesktopModules\Repository\Templates folder. Each skin is in a folder with that is the same name as the skin. So, for example, the 'default' skin templates would be found in DesktopModules\Repository\Templates\default. However, this folder is not accessible via the DotNetNuke File manager, so the only way to upload a new skin or modify an existing skin would be via FTP.
In this release, the Repository Module will also look in Portals\#\RepositoryTemplates when accessing the skin template files. The Portals location takes precedence and files are combined at runtime with the files in the DesktopModules path. You do not have to copy ALL the skin files, just the ones you want to modify
So, a real-world example. . . .
You like the default repository skin, but want to change the style of the Title from Head to MyTitleClass, and do not want to have an image thumbnail at all. Here's what you would do...assuming this is for your Portal #0 ...
1) in the Portals\0 folder, create a new folder named 'RepositoryTemplates'
2) In the new RepositoryTemplates folder, create a new folder named 'default'
3) copy the default\template.html and default\template.xml files to a local folder on your work machine
4) edit the template.xml file and change the <CssClass> setting for the [TITLE] tag to "MyTitleClass"
5) edit the template.html file and remove the [THUMBNAIL] tag from the html
6) upload the modified template.html and template.xml files via the Admin->File Manager page and place the 2 new files in the Portals\0\RepositoryTemplates\default folder.
That's it. At runtime, the module will use the 2 modified files from the Portals folder and all other skin files from the DesktopModules path.
To create a brand new skin, copy the skin folder that's closest to what you want to design in the DesktopModules\Repository\Templates folder and paste it in the same location with the name of the new skin you're building. Then you can either modify the files in your new folder directly, or create a folder in the Portals\0\RepositoryTemplates folder and place only the files you modify.
If you have any questions or problems, just ask here and we'll help you out.